Processing steps in refineries or other manufacturing plants frequently require or generate high temperatures. Typically, a process such as a fluid catalytic cracking step requires valves capable of efficient and reliable operation in hostile environments. These valves must resist the erosive forces of high temperature gases and/or solids entrained therein. These gases can have a temperature of 1800.degree. and even higher in some instances. The impact of fluid entrained particles flowing at high velocities tends to erode valve components projecting into the fluid stream.
The valves most commonly used in high temperature gas applications are slide valves and plug valves. These valves feature single or multiple slides or plugs operating in a plane generally perpendicular or parallel to the direction of fluid flow in the valve, thereby controlling flow, as needed. These valves also employ an orifice section which may be located upstream or downstream of the slide or plug depending upon the design employed. The orifice edges as well as the edges of the slides or plugs exposed to the fluid flow frequently experience severe erosion. To prevent erosion of costly valve components which would require lengthy downtime for valve replacement, sacrificial wear tabs have been placed on the exposed orifice edges of plugs or slide edges most likely to experience severe erosion. Periodically, these valves are inspected and the wear tabs are replaced. Replacement of the wear tabs is a far simpler, quicker and more economical process than repairing or replacement of frequently large and costly valve components.